Proposal of De Novo Antigen Test for COVID-19: Ultrasensitive Detection of Spike Proteins of SARS-CoV-2.

Polymerase chain reaction (PCR)-based antigen tests are technically difficult, time-consuming, and expensive, and may produce false negative results requiring follow-up confirmation with computed tomography. The global coronavirus disease 2019 (COVID-19) pandemic has increased the demand for accurate, easy-to-use, rapid, and cost-effective antigen tests for clinical application. We propose a de novo antigen test for diagnosing COVID-19 using the combination of sandwich enzyme-linked immunosorbent assay and thio-nicotinamide adenine dinucleotide (thio-NAD) cycling. Our test takes advantage of the spike proteins specific to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The limit of detection of our test was 2.3 × 10-18 moles/assay. If the virus has ~25 spike proteins on its surface, our method should detect on the order of 10-20 moles of virus/assay, corresponding to ~104 copies of the virus RNA/assay. The detection sensitivity approaches that of PCR-based assays because the average virus RNA load used for PCR-based assays is ~105 copies per oro- or naso-pharyngeal swab specimen. To our knowledge, this is the first ultrasensitive antigen test for SARS-CoV-2 spike proteins that can be performed with an easy-to-use microplate reader. Sufficient sensitivity can be achieved within 10 min of thio-NAD cycling. Our antigen test allows for rapid, cost-effective, specific, ultrasensitive, and simultaneous multiple measurements of SARS-CoV-2, and has broad application for the diagnosis for COVID-19.

Prognostic significance of low pre-transplant skeletal muscle mass on survival outcomes in patients undergoing hematopoietic stem cell transplantation.

Little is known about the prognostic significance of muscle loss for allogeneic hematopoietic stem cell transplantation (allo-HCT). We retrospectively analyzed consecutive patients who received allo-HCT from 2013 to 2015. All patients underwent computed tomography (CT) imaging and bioelectrical impedance analysis (BIA) within 30 days before allo-HCT. Skeletal muscle area (cm2) at the third lumbar vertebra level on CT imaging and skeletal muscle mass (kg) measured by BIA were normalized by height in meters squared (m2) to calculate the skeletal muscle area index (SMI) and skeletal muscle mass index (SMMI). SMI and SMMI were significantly correlated (r = 0.744; P < 0.001). The cumulative incidence of 1-year non-relapse mortality (NRM) was significantly higher in patients with low SMI than high SMI (17% versus 0%, respectively; P = 0.023). Overall survival was shorter in patients with low SMI than high SMI (56% versus 93%, respectively; P < 0.001). In univariate analysis, low SMI was associated with increased risk of NRM (HR 7.46; 95% CI 1.05-52.98; P = 0.044), and in multivariate analysis it was associated with higher overall mortality (HR 5.35; 95% CI 1.71-16.72; P = 0.004). These results suggest that low muscle mass is an independent predictor of mortality after allo-HCT.

Risk of low bone mineral density in patients with rheumatoid arthritis treated with biologics.

BACKGROUND: Osteoporosis is a complication of rheumatoid arthritis (RA). We identified risk factors for osteoporosis during treatment with biologics. METHODS: Femoral neck bone mineral density (BMD) was measured in 186 patients with biologics-treated RA. We compared the characteristics of those with BMD ≥70% of young adult mean (YAM) and those with BMD <70% of YAM, and undertook multivariable logistic regression analysis to identify risk factors for bone loss. RESULTS: Mean age and disease duration, the proportion of females, scores in the Modified Health Assessment Questionnaire and history of vertebral fracture were significantly greater in the BMD <70% of YAM group, but body mass index (BMI) was significantly lower in the BMD <70% of YAM group. There was no significant difference between the groups in terms of other biomarkers of RA activity, the proportion treated with methylprednisolone, or the duration or choice of biologics. The proportions of patients treated with anti-osteoporosis drugs and parathyroid hormone were significantly higher in the BMD <70% of YAM group. In the multivariable analysis, advanced age, female, longer disease duration, history of past thoracic or lumbar vertebral fracture, higher Steinbrocker classification and lower BMI were significant factors for BMD <70% of YAM. DISCUSSION: We identified risk factors for bone loss in patients with RA treated with biologics. Before suppression of disease activity by biologics, bone loss might already be advanced. CONCLUSIONS: We recommend that patients with RA who possess these risk factors be considered for earlier and more intense treatment to prevent bone loss, as well as addressing RA disease progression.

Clinical manifestations of human T lymphotropic virus type I-infected patients with systemic lupus erythematosus.

OBJECTIVE: Human T lymphotropic virus type I (HTLV-I) may be associated with some connective tissue autoimmune diseases, including systemic lupus erythematosus (SLE). To determine the relationship between HTLV-I infection and SLE, we examined the clinical manifestations of SLE patients with HTLV-I infection. METHODS: Eighty-nine patients with SLE were screened for antibodies to HTLV-I by electrochemiluminescence immunoassay. The presence of HTLV-I proviral sequences in peripheral blood mononuclear cells (PBMC) was determined by real-time polymerase chain reaction (PCR) quantification and Southern blotting analysis. The differences in clinical manifestations between HTLV-I-seropositive and seronegative patients with SLE were analyzed statistically. RESULTS: Fourteen of 89 (15.7%) patients were HTLV-I seropositive. All PBMC samples from 11 patients tested by PCR and 3 samples from 10 patients tested by Southern blotting analysis were positive for HTLV-I-related sequences. The age of HTLV-I-seropositive patients with SLE was significantly higher than that of seronegative patients (median 60 vs 42 yrs; p < 0.0005). The age at onset of SLE in HTLV-I-seropositive patients was also significantly higher than that of seronegative patients (median 45.5 vs 30 yrs; p <0.0005). The lymphocyte count in HTLV-I-seropositive SLE patients was significantly higher than that of seronegative patients (median 1740 vs 1066/microl; p = 0.027). The maintenance dose of prednisolone in HTLV-I-seropositive patients with SLE was significantly lower than that in seronegative patients (median 5 vs 9 mg/day; p = 0.012). CONCLUSION: This is the first report of the differences in clinical manifestations between SLE patients with and without HTLV-I infection. Our results suggest some involvement of HTLV-I in the pathogenesis of SLE.

Stevens-Johnson syndrome induced by mizoribine in a patient with systemic lupus erythematosus.

A 32-year-old Japanese woman, who had a treatment history of systemic lupus erythematosus (SLE) with lupus nephritis World Health Organization class IV for 11 months, visited our hospital due to fever, facial erythema, and erosion of the oral cavity on November 10, 2003. Her mucosal erosion and facial skin erythema progressed over the following week, and Stevens-Johnson syndrome was diagnosed due to pathological findings of the skin. Among the administrated drugs, only mizoribine, started 6 months earlier, produced a positive reaction in the drug lymphocyte stimulation test. Increased prednisolone and high dose intravenous gamma-globulin were given successfully. Cyclosporine at 50 mg was administered to control the SLE, followed by an increase to 100 mg on January 7, 2004. She suffered from abdominal pain, blindness, and convulsion on January 9. The magnetic resonance image of her brain prompted a diagnosis of reversible posterior leukoencephalopathy syndrome. After withdrawal of cyclosporine and control of hypertension, symptoms disappeared rapidly. Cyclophosphamide pulse therapy was successfully administrated to control lupus nephritis. This is the first report describing the relationship between Stevens-Johnson syndrome and mizoribine. Although the use of mizoribine is thought to be safe, careful observation is necessary.